6th INTERNATIONAL CONFERENCE ON SUSTAINABLE DEVELOPMENT, 6 - 07 Kasım 2020, ss.2-3
Many industrial
processes discharge organic chemicals into water, and some of these chemicals
are not only toxic but also have limited biodegradability. Thus, it is
necessary to develop effective methods for degrading these pollutants.
Azo dyes are the
largest group of the synthetic colorants which consists of azo groups (–N=N–)
in association with aromatic systems and auxochromes (-OH, -SO3,
etc.) A typical example of azo dyes, Acid Orange 7 (AO7) is widely used in many
industries such as pulp, textile, printing, leather and cosmetic. AO7 dyes may
cause serious environmental problems because of their toxic and/or carcinogenic
effects. At this point, biological conventional methods are often not
sufficient. Therefore, there is great interest in the advanced oxidation
processes (AOPs). The most popular AOP is the electro-fenton (EF) process based
on formation of hydroxyl radicals (•OH)
in the presence of Fe2+/ Fe3+ as catalyst and H2O2
as an oxidant.
On the other hand,
the most important point in the EF process is the electrode selection. At this
point, carbon felt electrodes are an important alternative to other
carbon-based electrodes due to their advantages.
In this study, the efficiencies of
thermal modified carbon felts as working electrode were tested in an on-line EF
system with Ti/RuO2-IrO2-TiO2
plate anode and SCE reference electrode for dye and TOC removals of AO7
solution (0.1 mM). To test the effectiveness of dye and TOC removal, the modification
temperature (400-900˚C -1h) under N2 atmosphere were investigated in
cathodic potential (0.8V), pH (3), Fe2+(0.3mM) and Na2SO4
(50mM). Finally, the modification temperature was selected as 900˚C due to
maximum dye and TOC removal efficiencies